An agricultural harvester, in operation, carries a header for cutting crop material and transporting the crop material to the feeder of the agricultural harvester. The header is connected to the header mounting frame of the agricultural harvester. In recent years the dimensions of the header, and particularly the width of the header, has significantly increased so that also the weight of the header is significantly higher today. The width of the header requires the header mounting frame to be pivotally mounted to the feeder, directly or indirectly, to allow a lateral tilt movement of the header mounting frame with respect to the feeder. This lateral tilt movement is actuated by at least one lateral tilt actuator so that lateral tilt of the header can be automatically adjusted while operating the agricultural harvester. Such lateral tilt movement prevents the end segments of the header from touching the ground surface when the ground surface is uneven.
EP 2 172 095 describes a further evolution of an agricultural harvester, wherein the header mounting frame is not only able to automatically rotate in a lateral tilt movement, but is also able to automatically move in a fore-aft movement. Tests have shown that an ideal angle between the ground surface and the header cutting elements provided at the leading edge of the header depends on multiple parameters, for example the type of crop material to be harvested. EP 2 172 095 describes a feeder which is pivotally connected to an intermediate frame, so that the intermediate frame can rotate around an axis that is substantially horizontal and transverse to the forward driving direction of the agricultural harvester, and wherein a fore-aft actuator is provided which extends between the intermediate frame and the feeder to actuate a rotation of the intermediate frame with respect to the feeder. Furthermore, the intermediate frame is pivotally connected to the header mounting frame to enable a rotation of the header mounting frame with respect to the intermediate frame around an axis that is substantially horizontal and parallel to a forward driving direction of the agricultural harvester, and wherein a lateral tilt actuator is provided between the intermediate frame and the header mounting frame to actuate rotation of the header mounting frame with respect to the intermediate frame, thereby actuating the lateral tilt movement of the header. A major advantage of such set-up is that both the lateral tilt movement and the fore-aft movement can be automatically adjusted via respective actuators, so that an optimal position of the header can be obtained by steering the lateral tilt actuator and the fore-aft actuator into their respective optimal positions. This significantly facilitates the use of the agricultural harvester for an operator since the operator is able to remotely adjust the fore-aft position of the header as well as the lateral tilt position of the header.
A draw-back of the known system is that due to the increase in width and weight of the header of the past years, the tension and forces on the connection points between feeder and intermediate frame and between intermediate frame and header mounting frame, during normal operation of the harvester, are so high that any unexpected impact on the header can result in damage or breaking of these connection points. Recent tests have illustrated this, when an agricultural harvester literally drove over a header which broke off from the harvester when the connection between the intermediate frame and a header mounting frame was overloaded.
It is an object of the present invention to provide an agricultural harvester wherein the header mounting frame can be automatically adjusted in the fore-aft movement and in the lateral tilt movement, and wherein the header mounting frame is more rigidly connected to the feeder.